Move template in-class function definitions out of class

Keeping them defined in-class caused linker issues with the extern template
declaration in a non-optimized MinGW debug build. Apparently it did not
inline them but instead relied on the extern declaration and expected
them defined somewhere else.

src/blackmisc/pq/physicalquantity.cpp

@@ -41,6 +41,18 @@ namespace BlackMisc
 {
     namespace PhysicalQuantities
     {
+        template <class MU, class PQ>
+        const MU & CPhysicalQuantity<MU, PQ>::getUnit() const
+        {
+            return m_unit;
+        }
+
+        template <class MU, class PQ>
+        void CPhysicalQuantity<MU, PQ>::setUnit(const MU &unit)
+        {
+            m_unit = unit;
+        }
+
         template <class MU, class PQ>
         void CPhysicalQuantity<MU, PQ>::setUnitBySymbol(const QString &unitName)
         {